Palletized loads are conventionally stored on rack systems in warehouses, with each pallet being placed spanning a pair of horizontal support beams which run adjacent to and parallel to an aisle. The pallet handling equipment moves along the aisle and can be raised and lowered to deliver palletized loads to empty positions in the rack and to retrieve palletized loads from filled positions.
The handling equipment may be a platten unit which has one or two horizontally and telescopically extending lifting arms or plattens designed to fit beneath a pallet and lift the pallet and its load. The plattens may be extensible to either side of the platten unit body so that collection of pallets from and delivery of pallets to both sides of the aisle is possible. Such a platten unit is said to be a double reach telescopic unit.
Continental European pallets conventionally comprise top boarding which provides a top surface or goods supporting platform, and three rows of legs or runners on which the top boarding is supported. The plattens of a platten unit for pallet handling contact the bottom surface of the top boarding to lift the loaded pallet.
One problem encountered by pallet handling equipment is that not all pallets conform to the above standard. Most British pallets, as well as those of many other countries such as the USA, generally comprise additional bottom boarding which gives the pallets additional stability and strength. The platten or plattens of a platten unit for pallet handling contact the underside of the bottom boarding, which extends across some or all of the underside of the pallet. Therefore a pallet with top and bottom boarding cannot be set down on a level surface or on a pair of horizontal beams of conventional warehouse racking without providing some means for removing the plattens while the level surface or horizontal beams takes the weight of the loaded pallet. This problem has in the past been met by providing packing pieces for the warehouse racking. Each bay of the racking system is provided with two horizontal beams, and each beam is provided with two packing pieces being load-bearing members which straddle the beam on which they are mounted and present a load-bearing surface for supporting a pallet a spaced distance above the beam. A pallet with top and bottom boarding can then be placed on the array of four packing pieces in the racking bay, and the plattens can be withdrawn through the spaced distance separating the bottom of the pallet and the beams This solution does however carry its own drawbacks since four packing pieces are required per bay: packing pieces are costly to secure in place; and additional storage height is required to accommodate the packing pieces.
The invention provides a pallet handling platten unit for use with pallets with top and bottom boarding, which avoids the above disadvantages.